Spin Microscopy Lab
Nitrogen-vacancy (NV) defects in diamond crystals are playing an essential role in the development of new nanoscale sensing devices based on the quantum properties of NV defects. We are occupied with the following endeavours:
- How can the quantum properties of the NV defect spin be controlled for improved quantum sensing tasks?
- What new nanoscale magnetic field sensing modalities can NV defects enable?
- How can we apply the NV nanomagnetometry toolbox, which offers high sensitivity and high spatial resolution, for the study of magnetic samples such as 2D magnetic materials having nanoscale volumes?
News
July 2024
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Project Associate Anshul Poonia presented a poster at the “Women in Quantum Science and Technologies” conference held in Kolkata.
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Dr. Phani Kumar visited TIFR Hyderabad on the 2nd of July and gave an invited seminar.
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Dr. Sourav Chatterjee from TCS Research, Kolkata visited our research lab to explore and identify synergies of applying quantum sensing research being pursued in our lab.
June 2024
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Dr. Phani Kumar gave an invited talk at the Second Conference on Force Spectroscopy and Microscopy in Casuarina Resort, Kurunji.
May 2024
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S. John Sharon Sandeep, BS-MS student from the Department of Physics has joined the group to pursue the summer internship sponsored by Tata Consultancy Services - Research and Innovation.
April 2024
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https://t.ly/cbmlb
Our research group is proud to announce the introduction of a postgraduate lab experiment on “Magnetometry with diamond quantum defects”, the first of its kind in India, as part of BS-MS PHY curriculum in the academic year 2023-24. It provides students with valuable hands-on exposure to diamond magnetometry techniques. Developing magnetometers with high sensitivity is one of the main objectives of the National Quantum Mission approved by the Union Cabinet and launched by DST India.
February 2024
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Ph.D student Shashank Kumar received the best poster presentation award at the National Physicists’ Conclave 2024 organised by SRMIST, Kattankulathur.
November 2023
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Dr. Phani Kumar gave an invited talk at the National Conference on Quantum Condensed Matter in NISER, Bhubaneswar.
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Ph.D. student Pralekh Dubey presented a poster at the annual international conference on “Recent Progress in Graphene and 2D materials Research” held in Bengaluru.
July 2023
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Dr. Phani Kumar gave an invited talk at the Quantum Technologies: Introduction, Materials and Devices conference in IISER, Pune.
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Dr. Phani Kumar gave an invited talk at the Introduction to Precision Measurements and Quantum Metrology conference in ICTS, Bengaluru.
December 2022
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Dr. Phani Kumar gave an invited talk at the Modern Trends in Molecular Magnetism (MTMM) conference in IIT, Kharagpur.
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Ph.D. student Pralekh Dubey presented a poster at the 2nd Asian Conference on Molecular Magnetism in IISER, Bhopal.
March 2022
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Ph.D. student Shashank Kumar gave an online contributed talk at the APS March Meeting in Chicago.
December 2021
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Dr. Phani Kumar gave an online invited talk at the conference MRSI AGM 2021.
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Dr. Phani Kumar gave an online contributed talk at the National Conference on Quantum Condensed Matter.
Dr. Phani Kumar
Principal Investigator
Research Interests
Nitrogen-vacancy (NV) spins in diamond, Quantum sensing, Atomic force microscopy, Nano-spin-mechanical systems (NSMS), Nanomagnetism, Hybrid quantum sensors, Nanoscale scanning diamond probes, Magnetic resonance imaging, Biosensing, Quantum technology, Confocal microscopy, Laser interferometry
Academics
Postdoc [July 2013 - November 2017]
Institute for Quantum Optics, University of Ulm, Germany
Advisor: Prof. Fedor Jelezko
Research: Quantum Sensing, Diamond Magnetometry, Nano-spin-mechanical Systems (NSMS)
Section on Quantum Physics and Information Technology, Technical University of Denmark, Copenhagen
Advisor: Prof. Ulrik Andersen
Research: Nanomechanics
Division of Physics and Applied Physics, Nanyang Technological University, Singapore
Research: Spin Centers in Silicon Carbide
PhD
[Department of Physics, University of Basel, Switzerland (April 2009 - June 2013)]
Thesis: Magnetic resonance force microscopy: Harnessing nuclear spin fluctuations.
Advisor: Prof. Martino Poggio
Research: Apart from making contributions to setting up of a low temperature high vacuum
magnetic resonance
force microscopy (MRFM) setup, I explored a novel approach using MRFM to harness the naturally occurring
random
fluctuations in nanoscale ensembles of nuclear spins.
MSc
[Micro and Nanosystems, ETH Zurich, Switzerland (October, 2006 - January, 2009)]
Thesis: Efficient coupling to photonic crystal cavities.
Advisor: Prof. Atac Imamoglu
Courses Credited:
Quantum Mechanics for Nanosystems, Advanced Optoelectronics, Quantum Optics, Quantum Systems for
Information Technology,
Magnetism: from the Atom to the Solid State, Advanced Solid State Physics, Statistical Physics,
Semiconductor Nanostructures,
Quantum Optics and Semiconductor Quantum Dots
Course Projects:
MATLAB simulations for gain calculations of quantum dot laser
BTech
[Indian Institute of Technology, Madras (September, 2001 - July, 2005)]
Courses Credited: (GPA - 8.56/10)
Physics - I, Physics Lab - I, Electrodynamics, Physics Lab - II, Quantum Mechanics for Engineers,
Semiconductor
Physics, Dynamical Systems, Laser Theory, Mathematical Physics, Superconductivity and its Applications
Achievements
- Pratibha scholarship awarded by Andhra Pradesh state government for BTech studies in IIT Madras
- Indian Institutes of Technology-Joint Entrance Examination (IIT-JEE) 2001 Rank: 532 (out of 1,70,000+ students) for admission to IITs
- Secured an All India Rank of 8 (99.81 percentile) in Joint Entrance Screening Test (JEST) Physics 2009 for admission to Ph.D programmes
- Achieved a score of 890/1000 (90 percentile) in GRE Physics 2005, an examination taken by applicants for admission into graduate schools in USA
Research
SINGLE-SPIN MAGNETOMETRY
We develop nitrogen-vacancy (NV) spin-based diamond magnetometers capable of measuring the minute magnetic fields with high sensitivity and spatial resolution. Our aim is to utilize the diamond spins as scanning probes to spatially map the tiny magnetic fields on the nanoscale. This would allow us to obtain a greater understanding of the magnetic phenomena which are otherwise not discerned by global magnetization measurements due to spatial averaging.
HYBRID NV-DIAMOND SENSORS
We also apply NV centers as nanoscale probes of stress, temperature and electric fields. Standard NV-diamond sensing devices when combined with the strategy of hybridization offer a huge potential for improving their sensitivity. Such hybrid quantum sensors may provide a novel approach for studying a broad range of physical processes on the nanoscale.
Publications
Microwave polarization-assisted vector magnetometry using nitrogen-vacancy centers in diamond
Manuscript under preparation
High-resolution spectroscopy of a single nitrogen-vacancy defect at zero magnetic field
Quantum Sci. Technol., 2023, 8, 025011 pdf
Scalable fabrication of single silicon vacancy defect arrays in silicon carbide using focused ion beam
ACS Photonics, 2017, 4(5), 1054-1059
Nanomechanical sensing using spins in diamond
Nano Lett. (2017), 17 (3), 1496-1503
Boundary between the thermal and statistical polarization regimes in a nuclear spin ensemble
Appl. Phys. Lett.105, 043112 (2014)
Harnessing nuclear spin polarization fluctuations in a semiconductor nanowire
Nature Physics 9, 631-635 (2013)
Feedback cooling of cantilever motion using a quantum point contact transducer
Appl. Phys. Lett. 101, 133104 (2012)
Measurement of statistical nuclear spin polarization in a nanoscale GaAs sample
Phys. Rev. B 84, 205328 (2011)
A geometry for optimizing nanoscale magnetic resonance force microscopy
Appl. Phys. Lett. 98, 163103 (2011)
Teaching
| August - November | January - April |
|---|---|
Members
PhD Students
Name: Shashank Kumar
Email: shashankk19[AT]iiserb.ac.in
Joined: January, 2020
Name: Pralekh Dubey
Email: dpralekh[AT]iiserb.ac.in
Joined: August, 2021
BS-MS Students
Name: Sunny Kumar Gupta
Email: sunny20[AT]iiserb.ac.in
Joined: June, 2024
Project Associates
Name: Anshul Poonia
Email: anshulpoonia1996[AT]gmail.com
Joined: April, 2024
Name: Muhammed Niyasali M
Email: niyasalimachingal[AT]gmail.com
Joined: May, 2024
Research Interns
Name: Chinmaya Singh
Email: chinmaya19[AT]iiserb.ac.in
Joined: June, 2024
Name: Roshin G Vallatt
Email: roshin18[AT]alumni.iisertvm.ac.in
Joined: June, 2024
Alumni
BS-MS Students
- Alen Philip (Graduated from IISERB in 2019, Currently Optical Designer at ZEISS Group, Germany)
- Basim S. S. (Graduated from IISERB in 2019)
- Md Arshad (Graduated from IISERB in 2020)
- Subham Singh (Graduated from IISERB in 2020)
- Ritesh Kumar Singh (Graduated from IISERB in 2020)
- Sujeet Pani (Graduated from IISERB in 2021, Currently Graduate Student at the Center for Quantum Information and Control, University of New Mexico)
- Swayangprabha Shaw (Graduated from IISERB in 2022, Currently Graduate Student at the Department of Electrical and Computer Science Engineering, University of Arizona)
- Sudhan Bhadade (Graduated from IISERB in 2022, Currently Graduate Student at the Institute for Experimental Physics, University of Innsbruck)
- Jemish Naliyapara (Graduated from IISERB in 2023)
- Dershik Ayyathan (Graduated from IISERB in 2023, Currently Graduate Student at the Department of Physics, The Technical University of Munich)
- Yash Patel (Graduated from IISERB in 2024, Currently Graduate Student at New York University)
- Devang V Krishnan (Graduated from IISERB in 2024)
